17 February 2022: New article on niches of marine mammals in the European Arctic
Christian Lydersen, Tore Haug and Martin Biuw, members of the NAMMCO Scientific Committee, are co-authors on a new study focussing on the niches of marine mammals in the European Arctic, published in the journal Ecological Indicators. The article provides invaluable insights to the overlap of food web position and dietary specialisation of marine mammals in the Arctic, which impacts how adaptable a species may be to future ecosystem changes that are expected due to climate change.
The study examined isotopic and trophic niches using skin carbon and nitrogen stable isotope compositions from 10 Arctic species: blue, fin, humpback, minke, sperm and white whales, bearded and ringed seals, walrus, and polar bears. The team also analysed the dietary fatty acids in polar bears, walrus, and most of the studied whale species.
The analyses revealed clear species separation by trophic behaviour and carbon sources and little overlap between species. Arctic residents such as the bearded seal, walrus and white whale had the smallest isotopic niches. This means that they are likely most vulnerable to climate change and accompanying changes to the Arctic ecosystem. The strong niche partitioning between all studied species also means that each is invaluable to the ecosystem in its own way, and loss of any one species may negatively impact the structure and connectivity of the whole ecosystem.
The full study by MacKenzie et al. is available here: https://doi.org/10.1016/j.ecolind.2022.108661